Chemical injector for spray device

ABSTRACT

A spray device, such as one used with a pressure washer, includes a housing, a chemical container coupled to the housing, and a chemical conduit coupled to the container. The chemical conduit has an inlet and an outlet forming a chemical flow path therebetween. The spray device further includes a chemical flow controller allowing a user to adjust a chemical flow rate through the chemical conduit. Further, the spray device includes a water conduit forming a water flow path through the housing, the water conduit terminating at a spray orifice. The chemical flow path and the water flow path merge at a point proximate the orifice.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This is a continuation of U.S. application Ser. No. 12/436,634, filedMay 6, 2009, which is incorporated herein by reference in its entirety.

BACKGROUND

The present invention relates generally to the field of spray devices,such as spray guns for pressure washers and sprayers for garden hoses.More specifically the present invention relates to a system forcontrollably injecting a chemical, such as soap, solvent, pesticide, orfertilizer, into a water stream that is ejected from a spray gun,sprayer, or spray nozzle.

Spray devices, such as pressure washer spray guns, are used forcleaning, stripping, watering, and other functions. Some spray devicesinclude systems for injecting soap and other chemicals into the spraystream, such as devices employing a soaper nozzle (also called a soapnozzle). A user attaches the soaper nozzle to a spray gun, and when thespray device is activated, soap is incorporated into the water flow viaa venturi located on a typical pressure washer pump. The rate of soapinjected into the water flow is a function of water flow rate andpressure in the soaper nozzle and design of the venturi.

SUMMARY

One embodiment of the invention relates to a spray device having ahousing, a chemical container coupled to the housing, and a chemicalconduit coupled to the container. The chemical conduit has an inlet andan outlet forming a chemical flow path therebetween. The chemical flowcontainer allows a user to adjust a chemical flow rate through thechemical conduit. The spray device further has a water conduit forming awater flow path through the housing, the water conduit terminating at aspray orifice where the chemical flow path and the water flow path mergeat a point proximate the orifice.

The invention further relates to a nozzle system having a nozzle bodyforming a water flow path, the nozzle body having an inlet and a sprayorifice. The nozzle system further includes a chemical injection tube,the tube extending through a wall of the nozzle body and having a tubeoutlet substantially within the water flow path. Further, the nozzlesystem includes a coupling end of the nozzle body.

Another embodiment of the invention relates to a spray device having awater conduit forming a water flow path, the water conduit terminatingat a spray orifice. A chemical conduit forms a chemical flow path, thechemical conduit positioned within the water conduit and terminating ata chemical outlet. The chemical flow path and the water flow path mergetogether at the chemical outlet, and the water flow path surrounds thechemical flow path where the chemical flow path and the water flow pathmerge.

Alternative exemplary embodiments relate to other features andcombinations of features as may be generally recited in the claims.

BRIEF DESCRIPTION OF THE FIGURES

The disclosure will become more fully understood from the followingdetailed description, taken in conjunction with the accompanyingfigures, wherein like reference numerals refer to like elements, inwhich:

FIG. 1 is a pressure washer system including a pressure washer pump, anengine, a spray gun, and a chemical container according to an exemplaryembodiment.

FIG. 2 is a side view of a pressure washer spray gun according to anexemplary embodiment.

FIG. 3 is a side view of a pressure washer spray gun according toanother exemplary embodiment.

FIG. 4 is a sectional view of a garden hose sprayer according to anexemplary embodiment.

FIG. 5 is a side view of a garden hose sprayer according to anotherexemplary embodiment.

FIG. 6 is a side view of a garden hose sprayer according to yet anotherexemplary embodiment.

FIG. 7 is a sectional view of a chemical injector nozzle according to anexemplary embodiment.

FIG. 8 is a sectional view of a chemical injector nozzle according toanother exemplary embodiment.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Before turning to the figures, which illustrate the exemplaryembodiments in detail, it should be understood that the presentapplication is not limited to the details or methodology set forth inthe description or illustrated in the figures. It should also beunderstood that the terminology is for the purpose of description onlyand should not be regarded as limiting.

Referring to FIG. 1, a spray device is shown according to an exemplaryembodiment in the form of a pressure washer system 110. The pressurewasher system 110 includes a support frame 120 having wheels 122, ahandle 124, and a base plate 126. The support frame 120 also includes aholster 136 for a spray gun 150 and a hose reel 132 for a hose 130.Coupled to the base plate 126, the pressure washer system 110 includesan internal combustion engine 140, having a housing 142 and a recoilstarter 144. The engine 140 is configured to power a pump 146, such as ahigh pressure axial cam or triplex piston pump.

The hose 130 can couple the pump 146 to the spray gun 150, where thespray gun 150 includes a gun housing 154 containing a water flow conduit158 that extends to a spray nozzle 156. The spray gun 150 is coupled toa chemical container, the chemical container shown as a storage tankbackpack 160, having a cap 164 and shoulder straps 166. Chemicals storedin the storage tank backpack 160 may be transferred to the housing 154via a chemical tube 162. Within the housing 154, the chemical tube 162terminates within the water flow path, where chemicals are injected intowater flowing through the conduit 158 along the flow path.

The storage tank backpack 160 and chemical tube 162 are designed tocontain and inject a wide variety of chemicals in the water flow. Somechemicals include liquid chemicals, such as detergent, liquid soap,solvent, pesticide, fertilizer, weed killer, silt emulsion, and otherchemicals. Other embodiments employ other chemical containers, such aspowdered chemical containers (see, e.g., FIG. 6).

FIG. 2 shows a spray device, according to another exemplary embodiment,in the form of a pressure washer spray gun 214. The spray gun 214includes a handle 250 with a trigger 252, a shaft 254, and a housing220. A spray nozzle 210 is connected to the outlet 262. A water flowconduit passes through the spray gun 214, creating a water flow paththat flows into the inlet 260, out of the outlet 262, and then throughthe nozzle 210. In other embodiments, the nozzle 210 is integral withthe outlet 262. The spray gun 214 also includes couplings, such as amale quick connect inlet 260 and a female quick connect outlet 262. Inother embodiments, such as with garden hose sprayers, the couplingsinclude threaded male and female couplings, such as a three-quarter inchgarden hose coupling (see, e.g., FIG. 4).

A water flow valve (not shown) is coupled to the trigger 252, and ispositioned along the water flow path. When the trigger 252 is pulled,the water flow valve opens, allowing water to flow along the water flowpath. When the trigger 252 is released, a biasing member (e.g.,torsional spring, coil spring, flexible metal strip, etc.), returns thetrigger 252 to a forward position, correspondingly closing the valve andinterrupting the water flow path.

Still referring to FIG. 2, the spray gun 214 further includes a chemicalcontainer 230 coupled to a housing of the spray gun 214. The chemicalcontainer 230 is threaded onto a port 232 located on the housing 220. Inan exemplary embodiment, a chemical conduit 234 interfaces with contentsof the container 230. The chemical conduit 234 includes an inlet 236 andan outlet 238, where the inlet 236 is joined to the chemical containerand the outlet 238 is positioned co-annularly within the flow path. Thecontents flow through the chemical conduit 234 from the inlet 236 to theoutlet 238. In some embodiments, a one-way flow valve or check valveprevents the contents from flowing in the opposite direction. Placementof the chemical conduit outlet 238 in the flow path with the outlet 238facing in the direction of water flowing through the flow path allows aventuri to pull the contents from the chemical conduit 234.

Still referring to FIG. 2, a flow control valve 240 provides control forthe rate of chemicals flowing through the conduit 234. The flow controlvalve 240 includes a rotatable knob 242 for a user to raise and lower avalve gate 244 to adjust a cross-sectional area of the flow path. Duringtimes when a user desires a greater rate of chemicals flowing throughthe conduit 234, the gate 244 may be completely removed from the flowpath. During other times, when a user desires no chemicals flowingthrough the conduit 234, the gate 244 may completely obstruct the flowpath. During still other times, the user may desire some intermediaterate of chemicals flowing through the flow path, which may beaccomplished by partially raising or lowering the gate 244.

In other embodiments the chemical flow rate can be adjusted byre-orienting the outlet 238 relative to the flow path, changing theratio of static to dynamic pressure at the outlet 238. By directing theoutlet 238 away from the positive direction of the flow path, the flowrate of chemicals through the venturi will be reduced. Still otherembodiments employ other systems for controlling the flow rate ofchemicals through the chemical conduit 234.

FIG. 3 shows a side view of spray device according to another exemplaryembodiment, the spray device in the form of pressure washer spray gun314. The spray gun 314 includes a handle 350 with a trigger 352, aninlet 360, an outlet 362, and a housing 370. A water flow path extendsalong a water conduit (not shown) between the inlet 360 and the outlet362. The inlet 360 includes a threaded male hose coupling. The spray gun314 also includes a chemical injector 330 positioned along the flowpath, after the outlet 362 and before a spray nozzle 310, such thatchemicals may be injected into a water flow passing through the chemicalinjector 330 and sprayed from the nozzle 310. The chemical injector 330may be disengaged and decoupled from the outlet 362 and the nozzle 310,and instead the nozzle 310 may be directly coupled to the outlet 362,thus removing the chemical injector 330 from the flow path.

The chemical injector 330 includes a chemical container 332 with arefill top 334 and a chemical tube 336 having an inlet 340 and an outlet342. The inlet 340 is positioned proximate to a bottom of the chemicalcontainer 332, where gravity pools the chemicals. The outlet 342 ispositioned along a portion 320 of the water flow path passing throughthe chemical injector 330. A guide 338 is positioned along the flow pathto protect and channel the chemical tube in the flow path. A venturipulls chemicals from the container 332 into the flow path. In otherembodiments, the chemical injector coupling additionally includes aone-way flow valve, a flow control valve, and a shut-off valvepositioned along the tube 336 to modify the rate of chemicals flowingthrough the tube 336. The flow control valve and shut-off valve can bemanually controlled by a user.

FIG. 4 shows a side cross section of a spray device according to yetanother exemplary embodiment, in the form of a hose sprayer 410. Thehose sprayer 410 includes a housing 420 forming a flow path 412 endingat an orifice 414, the housing 420 including a handle 422 and a shaft424. A trigger 430 is coupled to the handle 422 and includes a waterflow valve 440. The handle also includes an inlet 432 with a femalethreaded coupling 434. A chemical injector system 450 is coupled to thehousing 420. The chemical injector system 450 includes a positivedisplacement pump 460 with a manual actuator button 462 and a screw-onchemical container 452.

A user may operate the chemical injection system 450 by pressing theactuator button 462. The actuator button 462 is connected to a piston464, where pushing the button 462 drives the piston 464 forward. Thehead of the piston 464 is adjacent to a chamber 466, where chemicalsfrom the container 452 fill the chamber 466. When the piston 464 slidesforward, the chemicals within the chamber push against a check valve 470at an end of the chamber 466 opposite to the piston 464. The check valve470 allows the chemicals to flow from the chamber 466 and into achemical conduit 472. As the user releases the actuator button 462, aspring 468 pushes the piston 464 back to the end of the chamber 466,creating a negative pressure in the chamber 466, which draws in morechemicals from the container 452. As such, the user may then press theactuator button 462 again to inject another load of chemicals throughthe check valve 470.

The water flow valve 440 includes a gate 442 coupled to the trigger 430,a guide path 444 for the gate 442, a coil spring 446 biasing the gate ina closed position. A user may pull the trigger 430 toward the handle422, which pushes the gate 442 along the guide path 444 and loads thespring 446. When the trigger 430 is pulled and the gate 442 has beenlifted, a flow of water is permitted to flow through the valve 440.However, when the trigger 430 is released, the gate returns to rest in avalve seat 448 to block the flow path.

Still referring to the embodiment of FIG. 4, the chemical conduit 472extends from the check valve 470, through the housing 420 of the sprayer410 and into the flow path. The conduit 472 is directed in the directionthat water flows along the flow path 412. Proximate to the orifice, theconduit 472 ends, merging the chemical flow with the water flow. In apreferred embodiment, the chemical conduit 472 extends beyond theorifice 414, while in other embodiments the chemical conduit 472 endsbefore the orifice 414.

Extending the chemical conduit 472 through and beyond the orifice 414helps to reduce turbulence of the flow and prevent back pressure intothe conduit 472. Surface tension between the water flow and the chemicalconduit 472 beyond the orifice 414 holds the flow together, reducingturbulence and allowing for a greater stream projection distance. Thedistance that the chemical conduit 472 extends from the orifice 414varies in different embodiments. According to an exemplary embodiment,the chemical conduit extends beyond the orifice 414 by at least onemillimeter, preferably by at least three millimeters, such as acentimeter. However according to another exemplary embodiment, thechemical conduit 472 is flush with the orifice 414.

Still referring to FIG. 4, in the flow path 412, a flow of water isguided through a turbulence control assembly. The turbulence controlassembly includes a first screen 480, a plurality of parallel runningconduits 482, and a second and a third screen 484, 486. The screens 480,484, 486 and the parallel running conduits 482 collapse air bubbles inthe flow, remove eddy currents in the flow, and guide the flow in aforward direction along the flow path 412, such that water flow exitingthe orifice 414 has reduced turbulence. Some embodiments include onlyone screen, while other embodiments include a plurality of screens withno plurality of parallel running conduits, and other combinations.

FIGS. 5 and 6 show two exemplary embodiments of spray devices in theform of spray guns 510, 610. The spray guns 510, 610 are ergonomicallydesigned to allow a user to controllably inject a chemical, such assoap, into a water stream passing through the spray guns 510, 610.Triggers 514, 614 coupled to handles 512, 612 of the spray guns 510, 610may be pulled to allow a flow of water to pass through the guns 510,610. The guns 510, 610 further include a chemical container port 520,620 for attaching a chemical cartridge 522, 622 to the spray guns 510,610.

The chemical cartridge 522 of the spray gun 510 slides into the port520. The cartridge 522 includes an actuator 530 mounted to a rear of thecartridge 522. A user may press the actuator 530, which pumps air intothe cartridge 522, creating a positive pressure in the cartridge 522,which drives chemicals 524 in the cartridge through a check valve (notshown), into the water flow.

The chemical cartridge 622 of the spray gun 610 is received into theport 620. A sliding release 630 on the top of a housing 632 of the gun610 releases a valve (not shown) that is configured to block access ofthe water flow to powdered chemicals within the cartridge 622. However,when the valve is released, a portion of the water flow is diverted tothe cartridge 622, where the water flow hydrates the chemicals, and thencarries the chemicals back into the rest of the water flow and out ofthe gun 610.

FIGS. 7 and 8 show spray devices according to other exemplaryembodiments, shown as nozzle systems 710, 810. Both nozzle systems 710,810 allow a user to attach nozzle bodies 712, 812 to pressure washerguns, hose sprayers, or directly to garden hoses for providing anability to inject chemicals into water flowing from the pressure washerguns, hose sprayers, or garden hoses. Both systems 710, 810 includeturbulence control assemblies 740, 840 including screens 742, 744, and842, 844, respectively, and arrays of parallel conduits 746, 846.

As shown in FIG. 7, the nozzle system 710 includes the nozzle body 712forming a water flow path 720 through the nozzle body 712. The nozzlebody 712 has an inlet 714 and a spray orifice 716. A chemical injectionport 760 is formed on the nozzle body 712. Extending through thechemical injection port 760 is a tube 762 having a tube outlet 764substantially within the water flow path 720. A coupling end 730 of thenozzle system 710 is integral with the nozzle body 712, where thecoupling end includes a threaded male coupling 732.

Adjacent to the chemical injection port 760, a guide 750 extends fromthe body 712 to direct the tube 762 into the water flow path 720. Fromthe guide 750, the tube 762 is directed through the array of parallelconduits 746 and into the spray orifice 716. As water flows past theoutlet 764 a venturi pulls chemicals into the water flow. A channel 770attaches to the outside of the nozzle body 712 and couples to thechemical injection port 760. The channel 770 provides a chemical flowpath 772 from a container (not shown).

As shown in FIG. 8, a chemical injection tube 862 of the nozzle system810 extends through the spray orifice 816. While the turbulence controlassembly 840 includes screens 842, 844 and the array of parallelconduits 846, the turbulence control assembly 840 further includes anoutlet 848 on the chemical injection tube 862, where the outlet 848extends beyond the orifice 816. Surface tension of water flowing overthe outlet 848 pulls the water together, further reducing turbulence. Inaddition a venturi at the outlet 848 pulls chemicals into the water. Thenozzle body 812 of the system 810 further includes a muzzle 890 or guardcoupled to a spray end of the nozzle body 812, where the muzzle 890protects the outlet 848 extending beyond the orifice 816.

The present disclosure shows various modes through which a chemical maybe injected into a water stream. Other embodiments may include remotecontrol modes, where a solenoid is remotely activated to drive apositive displacement pump or release a check valve coupled to achemical tube or conduit, to controllably inject chemicals into a waterstream. In some embodiments, the rate of injection is calculated andcontrolled by a computer, such as with automatically injectingfertilizer into facility sprinkler system.

The construction and arrangements of the spray device, as shown in thevarious exemplary embodiments are illustrative only. Although only a fewembodiments have been described in detail in this disclosure, manymodifications are possible (e.g., variations in sizes, dimensions,structures, shapes and proportions of the various elements, values ofparameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter described herein. Forexample, elements shown as integrally formed may be constructed ofmultiple parts or elements, the position of elements may be reversed orotherwise varied, and the nature or number of discrete elements orpositions may be altered or varied. In some embodiments, the spraydevice may be employed with lawn sprinklers applying fertilizer in awater flow, fire hoses applying flame retardant in a water flow, oralirrigators (i.e., water picks) (mouthwash), etc. The order or sequenceof any process, logical algorithm, or method steps may be varied orre-sequenced according to alternative embodiments. Other substitutions,modifications, changes and omissions may also be made in the design,operating conditions and arrangement of the various exemplaryembodiments without departing from the scope of the present invention.

What is claimed is:
 1. A high-pressure spray device, comprising: ahousing; a chemical container carried on the housing; a trigger coupledto the housing; a water flow valve operated by the trigger; a chemicalconduit coupled to the container, the chemical conduit having an inletand an outlet and forming a chemical flow path therebetween; a waterconduit forming a water flow path through the housing, the water conduitterminating at a spray orifice, wherein the chemical flow path and thewater flow path merge at a point before the spray orifice; and an inletto the water flow path for receiving a high-pressure water flow, theinlet comprising a high-pressure coupling.
 2. The device of claim 1,further comprising a one-way valve positioned along the chemical flowpath.
 3. The device of claim 2, further comprising a pump positionedalong the chemical flow path.
 4. The device of claim 3, wherein the pumpis a positive displacement pump having a pump inlet and a pump outlet.5. The device of claim 4, wherein the pump is configured to be manuallyoperated.
 6. The device of claim 5, wherein the pump is configured to bepowered by pushing an actuator.
 7. The device of claim 5, furthercomprising a manual actuator button coupled to the pump, wherein thepump operates in response to pressing of the manual actuator button. 8.The device of claim 1, wherein the chemical container is a screw-onchemical container fastened directly to the housing.
 9. The device ofclaim 1, further comprising a plurality of parallel conduits positionedalong the water flow path, wherein the plurality of parallel conduitsare configured to collapse air bubbles, remove eddies, and guide flow ina forward direction along the water flow path.
 10. The device of claim9, wherein the chemical conduit extends through a center of theplurality of parallel conduits such that the plurality of parallelconduits surrounds at least a portion of the chemical conduit, whichextends in parallel with the plurality of parallel conduits.
 11. Thedevice of claim 9, further comprising a screen positioned along thewater flow path.
 12. The device of claim 11, further comprising a secondscreen positioned along the water flow path, wherein the screen and thesecond screen are positioned on opposite sides of the plurality ofparallel conduits.
 13. The device of claim 1, further comprising apressure washer including a pump for providing the high pressure waterflow to the water conduit.